A cache replacement method indicates a method for deleting some information stored in a cache memory so as to fetch and store new data from a main memory because no desired information exists in the cache memory. In a related art, a least recently used (LRU) method and a least frequently used (LFU) method are used as the cache replacement method.
The LRU method is a method to delete the oldest information from the cache memory. In other words, the LRU method is a method to delete the least recently used information from the cache memory.
The LFU method is a method to delete the least used information from the cache memory. In other words, the LFU method is a method to delete the least frequently used information from the cache memory.
In the meantime, according to recent research, each content has its own life cycle. A life cycle of each content will be described in more detail with reference to FIG. 1.
FIG. 1 illustrates a graph representing a life cycle of content of a related art.
An example of a life cycle of Youtube video content for 90 days is illustrated in FIG. 1. Referring to FIG. 1, it may be seen that the number of views of the content increases at a breakneck speed for the first 1 to 5 days but since then it decreases in a form of a particular curve. As such, every content typically has its life cycle as shown in FIG. 1, and based on this, it is possible to predict future popularity of the content with the recent trend. However, in the related art, there has not been any cache replacement method that takes into account the life cycle of content and thus a problem arises that optimized cache replacement cannot be performed.